Dimpling tool



y 1946- R. A. HAWN ETAL 2,400,412

DIMPLING TOOL Filed June 18, 1943 ATTORNEY g Patented May 14, 1946 1.Claim.

This mason relates. to dimpling tools, .and'

more. particularly to; the construction offthe same.

.Withthe dimplin g tools used: heretofore, the ,constructionhasbeen: such that the tool itself takes-up considerable-space sothat the employmerit of thetool inanarrow spaces is practically prohibited; Also the operable parts". of the. sameare located externally of the tool andarefree to be engaged by. obstructionsupon movement of In;

the: t'oolnin. and; outiof. the diflicult places. other words,.theseoperableparts are left unprotected and hence: are readily put out of operation.

It is an object'of: the present invention to provide at dimplingj tool whichjslof simple construction, cheap tic-manufacture and adapted to: be

used: in confined-spaces. i, i v

It is another object of the inventionrto. provide adimpling tool which is. so. constructed that its- I operating parts are protected at all times and such thatthese partsgcan be readily disassembled so that they may-'bereplaced quickly when desired.

According to the present invention the dimpling tool comprises an anvil member having a solid or thick portion and a, depending skirt portion so connected with the thick portion as to provide a chamber within which is located a resilient operating or washer like rubber element adapted to bear against a collar portion on a peening memher to normally maintain the peening member Q out of its finally extended position within a central bore of the thick portion of the-anvil. This collar portion on the peening member not only serves to close off the chamber but serves as a means by which the peening member is locked to the anvil member. Within the chamber there is provided an annular recess into which is disposed at circumferentially 'expansible locking ring which, when seated in the recess, engages the collar portion of the peening member and prevents outward sliding movement thereof. When the peening member is maintained by the rubber element in a retracted position, a flared or countersink forming portion of the peening member, which serves to place the dimple in overlapped sheets of metal, is kept retracted so rubber within the chamber of the first anvil member. The result is a dimple adapted to con- -'tain a rivet such that it will be flush with the surfacezofitheoutermetallsheet,the actionof the tool being suchthat portionssaroundf the opening are free of cracks which would have weakened the union of the rivet with the sheetsl; Eorqotherlobjects and for a. better understanding; of; the: invention, referencermay be had to the following" detailed description: taken: in. connection with), the; accompanying drawing, in which Figure: 1? is a .view' of a .dimpling. arrangement withxthe: dimpling: tool: of thev present invention" shown-in across. section, .the dimple havingbeen formed within the'met'alsheets'. and:- the'peeningl memberstill inits finallyex-tended: position.

Fig.2: is"- aiview; similartoFig; 1', illustrating astepdn the. processprior to thepeening; memher having been locatedirr itsfinalflpositiori and.

withtheametali sheets lying? flat. on the dimpling 11001; i V I: 1', V s 7 Referring now particularly ,to:,Figs. l and 2,

thereisg-sh'own 'a dimpling-jtool; l0 having a. de-

pending-shank lfl= adapted" to fit within asocket element I2 of a dimpling press or arrangement. Securement of the shank II with the socket I2 is made bya screw I3. Also serving as a part of the dimpling press is an upper anvil l4 secured to a socket [5 by a screw IS, the socket l5 being movable and moving with it is the anvil Id.

The dimpling tool ID has a solid thick anvil portion ll with an anvil face l8 thereon. This anvil face is hollowed so. that as metal sheets [9 and 20 are depressed downwardly by the anvil M which has a slightly conical face2l thereon, they will be slightly buckled justprior to the operation of a peening member 22 having a flared or, countersink forming face 23 thereon. In the sheets l9 and 20 there are provided openings24 adapted to register with a pilot formation 25 on the peening member 22. The sheets I9 and 25 are simply disposed over the pilot formation 25 and'as the anvil M, with its flared hole I5 registering with the pilot formation, is brought down onto the anvil face IS, the sheets will be slightly concaved or buckled, all this being done just prior to the engagement of the flared face 23 of the peening member with the portions of the sheets about the openings 24.

Once this step in the process has been completed, extension of the peening member 22 is effected to finally form the dimple in the sheets l9 and 20. On the thick anvil portion I! is a depending skirt portion 26 serving to provide a chamber 21 within which there is located a washer like element 28 of resilient material,

such as rubber, surrounding the peening member 22 and adapted to bear against a collar formation "29 on the peening member. This washer element of resilient material is stifi enough to prevent relative movement of the peening member with respect to the anvil l'l while the sheets I9 and 20 are being brought flush between the anvil faces l8 and 2|. After that time there is relative movement between the peening member and the anvil l1 and the peening member'is forced upwardly through a central bore 30 to efiect the dimpling operation.

Portions 3| about the openings 24' in the sheets i9 and 20 are forced upwardly to make a clean countersink formation in the sheets, these portions being bent up at a sharp angle.

The collar formation 29 not only serves to close off the rubber element 28 within the chamber 2! but also serves as a means by which the peening member can be retained Within the 1 central bore 30 and coupled with the anvil H. The outer periphery of this collar portion engages a circumferentially expansible locking spring 32 adapted to snap into an annular recess 33 in the lower end of the skirt portion 26 of the anvil I1.

It will be seen that the parts of this dimpling tool can be readily assembled and locked together by simply locating the locking spring 32 within the recess 33. At any time it is desired to the location where the tool has been usedfi Also that the dimpling tool itself takes up very little head space and that it is therefore adapted for use in confined places.

While various changes may be made in the detailed construction, it shall be understood that such changes shall be within the spirit and scope of the present invention as defined. by the appended claim.

' We claim as our invention:

In a tool for'forming dimples in pre-punched sheet material, a unitary anvil having a working face and a bore opening centrally therethrough, the anvial bore being constituted by a reduced diameter section and an adjacent enlarged diameter section, said sections defining an internal wall therebetween, a peen constiduced diameter bore section and a second and enlarged body portion slidably mounted in the enlarged diameter bore section, said first body portion beingformed with a dimple forming end face which, upon relative sliding movement of said peen and anvil, isprojectable or retractable'relative to said anvil working face, and said second body portion defining'with' said internal wall and the wallet said enlarged diameter bore a chamber Within said anvil, and a rubber-like element mounted on-said first body portion and confined within said chamber for compression between said internal .wall. and 'the second body portion, said element: beingfisogdimensioned as to maintain the peen end-face: retracted with respect to said anvil working face when noncompressed-but being: deformable in a radial direction when compressed whereby said anvil and peen may slide relative to each other to project the peen end face relative to said anvil working face into-the sheet material to form a dimple. I I

RALPH A. HAWN.

IRVIN W. LACHER. 

